Towards a time-reversal mirror for quantum systems

The reversion of the time evolution of a quantum state can be achieved by changing the sign of the Hamiltonian as in the polarization echo experiment in NMR. In this work we describe an alternative mechanism inspired by the acoustic time reversal mirror. By solving the inverse time problem in a discrete space we develop a new procedure, the perfect inverse filter. It achieves the exact time reversion in a given region by reinjecting a prescribed wave function at its periphery.Comment: 6 pages, 4 figures. Introduction modified, references added, one figure added to improve the discussio

Role of PET/CT in the detection of liver metastases from colorectal cancer

The aim of this study was to compare the diagnostic accuracy of 2-[fluorine-18] fluoro-2-deoxy-D-glucose positron emission tomography (F-18-FDG-PET) and computed tomography (CT) with PET/CT in the detection of liver metastases during tumour staging in patients suffering from colorectal carcinoma for the purposes of correct surgical planning and follow-up. A total of 467 patients underwent a PET/CT scan using an iodinated contrast medium. We compared images obtained by the single PET scan, the single CT scan and by the fusion of the two procedures (PET/CT). The final diagnosis was obtained by histological examination and/or by the follow-up of all patients, including those who did not undergo surgery or biopsy. The PET scan had 94.05% sensitivity, 91.60% specificity and 93.36% accuracy; the CT scan had 91.07% sensitivity, 95.42% specificity and 92.29% accuracy. The combined procedures (PET/CT) had the following values: sensitivity 97.92%, specificity 97.71% and accuracy 97.86%. This study indicates that PET/CT is very useful in staging and restaging patients suffering from colorectal cancer. It was particularly useful when recurrences could not be visualised either clinically or by imaging despite increasing tumour markers, as it guaranteed an earlier diagnosis. PET/CT not only provides high diagnostic performance in terms of sensitivity and specificity, enabling modification of patient treatment, but it is also a unique, high-profile procedure that can produce cost savings

Involvement of subcortical brain structures during olfactory stimulation in multiple chemical sensitivity

Multiple chemical sensitivity (MCS) patients usually react to odour compounds and the majority of neuroimaging studies assessed, especially at the cortical level, many olfactory-related correlates. The purpose of the present study was to depict sub-cortical metabolic changes during a neutral (NC) and pure (OC) olfactory stimulation by using a recently validated 18F-2-fluoro-2-deoxy-D-glucose (FDG)-positron emission tomography/computer tomography procedure in 26 MCS and 11 healthy (HC) resting subjects undergoing a battery of clinical tests. Twelve subcortical volumes of interest were identified by the automated anatomical labeling library and normalized to thalamus FDG uptake. In both groups, when comparing OC to NC, the within-subjects ANOVA demonstrated a relative decreased metabolism in bilateral putamen and hippocampus and a relative increased metabolism in bilateral amygdala, olfactory cortex (OLF), caudate and pallidum. The between-groups ANOVA demonstrated in MCS a significant higher metabolism in bilateral OLF during NC. As in HC subjects negative correlations were found in OC between FDG uptake in bilateral amygdala and hippocampus and odor pleasantness scale, the latter positively correlated with MCS subjects\u27 bilateral putamen FDG uptake in OC. Besides FDG uptake resemblances in both groups were found, for the first time a relative higher metabolism increase in OLF in MCS subjects at rest with respect to HC was found. When merging this aspect to the different subcortical FDG uptake correlations patterns in the two groups, the present study demonstrated to describe a peculiar metabolic index of behavioral and neurological aspects of MCS complaints

Mutations in the Cardiac Ryanodine Receptor Gene (hRyR2) Underlie Catecholaminergic Polymorphic Ventricular Tachycardia

BACKGROUND: Catecholaminergic polymorphic ventricular tachycardia is a genetic arrhythmogenic disorder characterized by stress-induced, bidirectional ventricular tachycardia that may degenerate into cardiac arrest and cause sudden death. The electrocardiographic pattern of this ventricular tachycardia closely resembles the arrhythmias associated with calcium overload and the delayed afterdepolarizations observed during digitalis toxicity. We speculated that a genetically determined abnormality of intracellular calcium handling might be the substrate of the disease; therefore, we considered the human cardiac ryanodine receptor gene (hRyR2) a likely candidate for this genetically transmitted arrhythmic disorder. METHODS AND RESULTS: Twelve patients presenting with typical catecholaminergic polymorphic ventricular tachycardia in the absence of structural heart abnormalities were identified. DNA was extracted from peripheral blood lymphocytes, and single-strand conformation polymorphism analysis was performed on polymerase chain reaction-amplified exons of the hRyR2 gene. Four single nucleotide substitutions leading to missense mutations were identified in 4 probands affected by the disease. Genetic analysis of the asymptomatic parents revealed that 3 probands carried de novo mutations. In 1 case, the identical twin of the proband died suddenly after having suffered syncopal episodes. The fourth mutation was identified in the proband, in 4 clinically affected family members, and in none of 3 nonaffected family members in a kindred with 2 sudden deaths that occurred at 16 and 14 years, respectively, in the sisters of the proband. CONCLUSIONS: We demonstrated that, in agreement with our hypothesis, hRyR2 is a gene responsible for catecholaminergic polymorphic ventricular tachycardia

Pharmacological characterization of a new Ca2+ sensitizer

The benzimidazole molecule was modified to synthesize a Ca(2+) sensitizer devoid of additional effects associated with Ca(2+) overload. Newly synthesized compounds, termed 1, 2, 3, 4, and 5, were evaluated in spontaneously beating and electrically driven atria from reserpine-treated guinea pigs. Compound 3 resulted as the most effective positive inotropic agent, and experiments were performed to study its mechanism of action. In spontaneously beating atria, the inotropic effect of 3 was concentration-dependent (3.0 microM-0.3 mM). Compound 3 was more potent and more active than the structurally related Ca(2+) sensitizers sulmazole and caffeine, but unlike them it did not increase the heart rate. In electrically driven atria, the inotropic activity of 3 was well preserved and it was not inhibited by propranolol, prazosin, ranitidine, pyrilamine, carbachol, adenosine deaminase, or ruthenium red. At high concentrations (0.1-1.0 mM) 3 inhibited phosphodiesterase-III, whereas it did not affect Na(+)/K(+)-ATPase, sarcolemmal Ca(2+)-ATPase, Na(+)/Ca(2+) exchange carrier, or sarcoplasmic reticulum Ca(2+) pump activities of guinea pig heart. In skinned fibers obtained from guinea pig papillary muscle and skeletal soleus muscle, compound 3 (0.1 mM, 1 mM) shifted the pCa/tension relation curve to the left, with no effect on maximal tension and no signs of toxicity. Compound 3 did not influence the basal or raised tone of guinea pig isolated aorta rings, whose cells do not contain the contractile protein troponin. The present results indicate that the inotropic effect of compound 3 seems to be primarily sustained by sensitization of the contractile proteins to Ca(2+)

Quantitative and Qualitative Assessments of Retinal Structure with Variable A-Scan Rate Spectralis OCT: Insights into IPL Multilaminarity

The aim of this study was to evaluate the qualitative and quantitative differences between 20 and 85 kHz A-scan rate optical coherence tomography (OCT) images acquired by spectral domain OCT. The study included 60 healthy subjects analyzed with horizontal linear scans with a variable A-scan rate (SHIFT technology, Heidelberg Engineering, Heidelberg, Germany). The retinal thickness measurement of each retinal layer was performed in three different positions (subfoveal, nasal, and temporal). The qualitative assessment was performed by two independent observers who rated every image with a score ranging from 1 ("sufficient") to 3 ("excellent") on the basis of three parameters: visualization of the vitreo-retinal interface, characterization of the retinal layers, and visualization of the sclero-choroidal interface. No statistically significant differences in terms of retinal layer thickness between the two A-scan rate scans were observed (p > 0.05). The coefficient of variation of the retinal thickness values was lower in the 20 kHz group (25.8% versus 30.1% with the 85 kHz). The 20 kHz images showed a higher quality index for both observers. An inner plexiform layer (IPL) multilaminarity was detected in 78.3% of patients from the 20 kHz group and in 40% of patients from the 85 kHz group (p < 0.05)

Development of Disposables and Accessories for ROSES and Their In Vitro Experimentation

This paper describes the development of the disposables and accessories for ROSES (Robotic System for Endovascular Surgery). Initially developed exclusively for transcatheter percutaneous coronary angioplasty, it was later modified, initially leaving the components for angioplasty substantially unchanged to extend its use to endovascular transcatheter surgery. These disposables are used to translate gear rotations into catheter or guide wire advancement or retraction and rotation of their body through friction wheels. The use of a new cart was necessary for endovascular surgery, to which a system to measure forces opposed by the patient’s body to catheter advancement was added. Moreover, since some endovascular catheters present with large diameters, minor mechanical modifications were also performed on the robot actuator (RA), previously defined as a slave, in order to allow large catheters to be pushed, such as those needed for the repair of some big aneurysms or for TAVI. However, in doing this, the possibility of separating the disposables into two components, upper and lower, was found, which allows the extraction of the disposable without having to remove the catheter or guide wire already positioned. Finally, the disposables, whose development is illustrated here, were subjected to various versions and tests and the results are reported

FIP200 claw domain binding to p62 promotes autophagosome formation at ubiquitin condensates

The autophagy cargo receptor p62 facilitates the condensation of misfolded, ubiquitin-positive proteins and their degradation by autophagy, but the molecular mechanism of p62 signaling to the core autophagy machinery is unclear. Here, we show that disordered residues 326-380 of p62 directly interact with the C-terminal region (CTR) of FIP200. Crystal structure determination shows that the FIP200 CTR contains a dimeric globular domain that we designated the "Claw" for its shape. The interaction of p62 with FIP200 is mediated by a positively charged pocket in the Claw, enhanced by p62 phosphorylation, mutually exclusive with the binding of p62 to LC3B, and it promotes degradation of ubiquitinated cargo by autophagy. Furthermore, the recruitment of the FIP200 CTR slows the phase separation of ubiquitinated proteins by p62 in a reconstituted system. Our data provide the molecular basis for a crosstalk between cargo condensation and autophagosome formation

Diagnosi differenziale dei tumori parotidei: quali caratteristiche di risonanza magnetica considerare?

La finalità del nostro lavoro è di valutare le caratteristiche di risonanza magnetica (RM) tipiche dei tumori parotidei maligni e benigni. Questo studio retrospettivo si basa sulla valutazione di esami RM pre-chirurgici di 94 pazienti con tumori parotidei. I risultati istologici erano disponibili in tutti i casi; abbiamo analizzato 69 lesioni erano benigne (73%) e 25 maligne (27%): 44 adenomi pleomorfi, 18 tumori di Warthin, 7 tumori benigni di diverso istotipo, 6 carcinomi squamocellulari, 3 carcinomi ex-adenomi pleomorfi, 2 carcinomi mucoepidermoidi, 1 tumore adenoidocistico, 13 tumori maligni di diverso istotipo. Sono state valutate le seguenti caratteristiche RM: morfologia, sede, dimensioni, margini, intensità di segnale nelle sequenze T2-pesate e T1-pesate, impregnazione dopo mezzo di contrasto (mdc), intensità di segnale della porzione cistica, presenza o assenza di una capsula, diffusione perineurale, pattern di crescita extraghiandolare e linfoadenopatie laterocervicali. È stata effettuata un’analisi statistica per identificare le caratteristiche RM più indicative di malignità e per definire l’aspetto tipico degli istotipi più comuni. I parametri significativamente predittivi di malignità sono risultati i margini mal-definiti (p < 0,001), le linfoadenopatie (p < 0,001) ed il pattern di crescita infiltrativo (p < 0,001). Le caratteristiche tipiche dell’adenoma pleomorfo sono risultate l’iperintensità di segnale nelle immagini T2-pesate (p = 0,02), l’intensa impregnazione dopo mdc (p < 0,001) ed i margini lobulati (p = 0,04). Le caratteristiche tipiche del tumore di Warthin sono risultate le componenti iperintense nelle immagini T1-pesate (p < 0,001), la localizzazione nel processo parotideo inferiore (p < 0,001) e l’impregnazione post-contrastografica lieve/incompleta (p = 0,01). L’intensità di segnale nelle immagini T1-pesate e T2- pesate e l’impregnazione post-contrastografica si sono rivelate utili nella diagnosi differenziale tra adenoma pleomorfo e tumore di Warthin

VALUTAZIONE DI UN NUOVO TERRENO CROMOGENO SELETTIVO PER LA PRESENZA DI ENTEROBATTERI PRODUTTORI DI ESßL

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